1. Field of the Invention
The present invention relates to a device for coiling and uncoiling elongated goods, such as wire, cable or the like, onto a drum and comprising a support with driving means for a spreader arm, which is rotatably mounted on the support for coiling and uncoiling the elongated goods onto the stationary drum.
2. Discussion of the Background
Coiling and uncoiling wire, cable and similar elongated goods by means of a coiling device is per se previously known. During coiling by way of such known devices, the coiled goods are torsionally twisted, wherein one turn of coiling causes one turn of twisting. Counter-clockwise coiling causes clockwise twisting, and clockwise coiling causes counter-clockwise twisting. Uncoiling usually takes place in the opposite direction to the coiling. When all the coiled goods have been uncoiled as stated above there is no remaining twist, however, mechanical stress in the goods has resulted.
Owing to frictional resistance in the spreader arm and in the goods, twisting is not linear along the length of the goods but the portion last coiled will be twisted to a much greater extent as compared to a previously coiled portion of the goods.
The non-linearity of the twisting thus arisen during coiling, which causes mechanical stress in the elongated goods, is not acceptable in some situations.
To solve the problems pointed out above, the device according to the invention has a spreader arm which, at its side facing the goods, presents a gripping arm, arranged to guide the elongated goods substantially in a tangential direction relative to the periphery of the drum.
In a preferred embodiment of the device according to the invention, the gripping arm has a running track in the form of a curved V-profile. Advantageously, the surface of the running track contacting the goods is defined by feeding rollers, which are spherical in shape and which present a rolling resistance near zero to eliminate twisting of the elongated goods during coiling and uncoiling.
In order to provide a uniform layer of the elongated goods coiled onto the drum, the spreader arm is provided with a device for moving the gripping arm, so that the gripping arm moves along the width of the drum in accordance with the coiling or uncoiling of the goods.
For access to the end of the elongated goods for uncoiling, the device according to the invention is provided with a lifting and rotating table so as to make possible 180xc2x0 rotation of the drum coiled with goods before uncoiling is initiated. The lifting and rotating table is preferably disposed on a carriage, the wheels of which run on rails starting out from the support of the device.
The present invention further relates to a winding machine and an intermediate storage device having a coiling device of the above-mentioned kind and intended for feeding a cable when mounting the cable in the slots of a stator for an electric machine.
The device, the winding machine and the intermediate storage device is especially but not exclusively intended to be applied when mounting high-voltage cable, on a generator where high-voltage cable is used in the windings of the stator, which cable lacks the outer protective covering normally surrounding such cable.
When mounting such a cable in a stator for an electric machine, the cable is required to be completely free or nearly free from twist, i.e. twisting of the cable should be linear relative to the cable length. This implies that one turn of uncoiling from the drum arbitrarily along the length of the cable should be free or nearly free from twist. In particular the invented device is advantageous when used for an rotating electric machine of the type disclosed in WO-97/45919.
The cable is preferably of the kind having an inner core with a plurality of wires, an inner semiconductive layer surrounding the core, an insulating layer surrounding the inner semiconductive layer and an outer semiconductive layer surrounding the insulating layer, preferably with a diameter of about 20 to 200 mm and a conductor area ranging from 80 to 3000 mm2.